function Tab(el){
    this.e = document.querySelector(el);
    this.init();
}
Tab.prototype.init=function(){
    this.titleOver();
}
Tab.prototype.titleOver=function(){
    let ulLiObjs = this.e.querySelectorAll('ul li');
    ulLiObjs.forEach((item,i)=>{
        item.onmouseover = ()=>{
        this.titleChange(item);
        this.changeContent(i);
        }
    })
}
Tab.prototype.titleChange = function(item){
    this.e.querySelector('ul li.active').className = '';
    item.className = 'active';
}
Tab.prototype.changeContent = function(i){
    this.e.querySelector('ol li.active').className = '';
    let olLiObjs = this.e.querySelectorAll('ol li');
    olLiObjs[i].className = 'active'
}






